Sandals are strewn in the yard of the Dapchi Girls Science and Technical College staff quarters in the wake of the abduction. Aminu Abubakar / AFP / Getty Images DAPCHI, Nigeria — This much everyone can agree on. Just after sunset on the night of Feb. 19, a truck full of armed men rolled into Dapchi, a speck of a town in the vast semi-desert plains of northeastern Nigeria. Mounted with machine guns, the truck sped along the town’s single paved road to its destination — a squat yellow building with a green roof. This was the residential block of Dapchi Girls Science and Technology College, a government-run school where dozens of girls aged 10 to 18 were preparing to settle down for the night. The truck’s armed occupants jumped out. They raised their AK-47s, screamed “Allahu akbar,” and began pumping bullets into the air. When the schoolgirls came streaming out, the gunmen bundled them into the truck and took them to their hideout in a swampy border region around Lake Chad — three ...